820-00840 20v 0.5a no video

2informaticos

Administrator
Staff member
Now is time to clean ME.
The chip from other board has dirty ME.
If your board BIOS has corrupted ME region, the symptom is explained...
 

Outofwhack

Member
Ah ok thanks for setting me straight. Would you have a clean ME region binary I can use to overwrite the dirty one?

As I mentioned the EFI repo file I examined MBP141_0178_B00.fd following Piernovs instructional video for this MacBookPro14,1 had no MeRegionUpdateVolume so I could not take its binary.
 

Outofwhack

Member
Progress at last. That gives me a login screen and I can restart and get it every time :)
From reading the forum I assume I need to change SSN somewhere?? with a hex editor [which I assume is the serial number] and fix up checksum (Fsys?)

Can this be done without Medusa hardware?
What happens if ssn is not changed here?
Also I notice something strange in the BIOS Region.bin where I found ssn.
The last 4 chars of the serial number seems to appear, in part a few characters later. I would assume it is important to recreate this - am I correct?
e.g. <blah>.ssn..C02VK5B8HV22.hwc..HV22.son..MPXT2B/A.EOF..
 
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2informaticos

Administrator
Staff member
Good enough to change only SSN.
Do it on hex editor and fix Fsys checksum with Medusa.
There is a video to fix it with UEFITool also, on logi.wiki page.
 
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